* Required packages

 - libuuid-devel or uuid-dev
 - libmount-devel or libmount-dev
 - libblkid-devel or libblkid-dev
 - libselinux-devel or libselinux1-dev (*1)

 *1: required only if supporting SELinux context mount options without
     using libmount.  By default, libmount is used and support of the
     context mount depends on the libmount that distro provides.

* How to compile

 $ ./configure
 $ make

If /etc/mtab is not a symlink to /proc/self/mounts but a regular file
in the target system, run the configure script with --without-libmount
option:

 $ ./configure --without-libmount

This configures the build environment so as to make legacy
mount/umount helpers (mount.nilfs2 and umount.nilfs2), in which the
legacy mtab file is handled properly.

Most modern Linux distributions use libmount by default, and this is
the recommended configuration.  This option is primarily intended for
legacy environments or specialized configurations that still rely on a
writable /etc/mtab file.


* Installation path configuration

If your system is a 64-bit architecture and libraries are installed
into /usr/lib64 instead of /usr/lib, change the library directory with
--libdir option:

 $ ./configure --libdir=/usr/lib64

If you want to separate the library files into a subdirectory, specify
it as follows, for example:

 $ ./configure --libdir=/usr/lib64/nilfs

Modern Linux distributions follow the "UsrMerge" or "Bin-Sbin merge"
schemes.  The configure script automatically detects the system
hierarchy and adjusts the installation paths for core binaries
(mkfs.nilfs2, mount.nilfs2, nilfs_cleanerd, etc.):

 - Legacy: Installs to /sbin
 - UsrMerge: Installs to /usr/sbin
 - Bin-Sbin merge (e.g., Fedora Rawhide): Installs to /usr/bin

When installing to /usr/bin, the build system also attempts to create
compatibility symbolic links in /usr/sbin if that directory exists on
the target system.

You can manually override this detection using the following options:

 # Force installation into /usr/bin (Bin-Sbin merge style)
 $ ./configure --enable-usrmerge=bin

 # Force installation into /usr/sbin (UsrMerge style)
 $ ./configure --enable-usrmerge=sbin

 # Force installation into the traditional /sbin
 $ ./configure --disable-usrmerge

By default, if the option is omitted, the script probes the system's
directory configuration to determine the appropriate hierarchy.  If
the option is specified without a TYPE (i.e., --enable-usrmerge), it
defaults to "sbin" (/usr/sbin) to align with standard UsrMerge
practices.

Note: This option is significant even when /sbin is a symbolic link to
/usr/sbin (i.e., the physical installation destination is the same).
It ensures that the absolute paths used by the utilities to call other
binaries are consistent with the chosen hierarchy.


* Trouble shooting

If the blkid library in your environment is old and incompatible with
this package, you can use --without-blkid option:

 $ ./configure --without-blkid

However, use of this option is normally not recommended because it
disables the safety check of mkfs.nilfs2, which prevents users from
accidentally overwriting an in-use device.

You can compile the legacy mount.nilfs2 and umount.nilfs2 helpers
without support for SELinux context mount options (-o context=<context>,
etc):

 $ ./configure --without-libmount --without-selinux

For helpers built with mount library (libmount), support of the
context mount depends on the libmount that distro provides.

If you are having problems due to the missing nilfs2 disk format or
ioctl interface definition file (nilfs2_ondisk.h or nilfs2_api.h,
respectively), try installing the Linux kernel source or header file
package first.

If you still cannot install these files, or if you want to overwrite
them with files from this package, specify the
"--enable-uapi-header-install" option as an argument to the configure
script.  This will install the uapi header files included in this
package:

 $ ./configure --enable-uapi-header-install

Note that the utility package itself references bundled local header
files, so you don't need to install these files with this option to
build.


* How to get development sources

 $ cd your-work-directory
 $ git clone https://github.com/nilfs-dev/nilfs-utils.git

Before compiling the development sources, you need to run autogen.sh
script.  This is not required for packaged sources unless you changed
the configuration.
 
 $ cd nilfs-utils
 $ ./autogen.sh

* Developer's notes

The central resource for nilfs-utils development is the mailing list
(linux-nilfs@vger.kernel.org).

First, please read the following documents (in short, follow Linux
kernel development rules):

https://docs.kernel.org/process/coding-style.html
https://docs.kernel.org/process/submitting-patches.html

Then, check your patches with the patch style checker prior to
submission (scripts/checkpatch.pl) like the following example:

 $ ./scripts/checkpatch.pl <patch-file>
 ...
 <patch-file> has no obvious style problems and is ready for submission.